Comparison · Minerals
Ametrine vs Calcite
Ametrine and Calcite are easy to confuse because both are minerals. Ametrine is harder (Mohs 7) than Calcite (Mohs 3), so Ametrine will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Ametrine and Calcite
- Ametrine is harder (Mohs 7) than Calcite (Mohs 3), so Ametrine will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
- Hold a thin edge to the light: Ametrine is Transparent, Calcite is transparent.
- They overlap in yellow, but Ametrine also comes in purple and Calcite also comes in clear, orange, blue, green, and pink.
- Well-formed crystals give it away: Ametrine is Trigonal, Calcite is trigonal.
Ametrine vs Calcite properties
| Property | Ametrine | Calcite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 7 | 3 |
| Luster | Vitreous | vitreous |
| Streak | White | White |
| Transparency | Transparent | transparent |
| Specific gravity | 2.65 | 2.7 |
| Crystal system | Trigonal | trigonal |
| Common colors | Purple and yellow bicolor zoning | Colorless, White, Yellow, Orange, Blue, Green, Pink |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$100+ |
Which is more valuable?
Ametrine is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Ametrine can reach $150 or more.
About Ametrine
Ametrine is a naturally occurring bicolor variety of quartz that combines the violet tones of amethyst with the golden hues of citrine within a single crystal. The color zoning arises from differing oxidation states of trace iron impurities distributed unevenly across growth sectors of the same silicon dioxide crystal. Most commercial ametrine traces back to a single deposit in Bolivia, though heat-treated material is also common in the gem trade.
About Calcite
Calcite is one of the most common minerals on Earth, found in sedimentary, metamorphic, and igneous rocks. It's the primary component of limestone and marble.
Ametrine vs Calcite FAQ
Is Ametrine the same as Calcite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Ametrine is harder (Mohs 7) than Calcite (Mohs 3), so Ametrine will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
How can you tell Ametrine from Calcite?
Ametrine is harder (Mohs 7) than Calcite (Mohs 3), so Ametrine will scratch Calcite and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Hold a thin edge to the light: Ametrine is Transparent, Calcite is transparent. They overlap in yellow, but Ametrine also comes in purple and Calcite also comes in clear, orange, blue, green, and pink.
Which is harder, Ametrine or Calcite?
Ametrine is harder: Mohs 7 against Mohs 3 for Calcite.
Which is more valuable, Ametrine or Calcite?
Ametrine is usually the more valuable of the two: a typical collector specimen runs about $20 against $15 for Calcite, and premium Ametrine can reach $150 or more.
